Helmet



FIG. 1 is a front, top and right side perspective view of a helmet showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof; and,

FIG. 6 is an enlarged view taken from within the area labeled “6” in FIG. 1.

The broken lines illustrate portions of the helmet that form no part of the claimed design. The dashed-dotted lines in the drawings denote the boundary of the claim and form no part of the claimed design. 

CLAIM The ornamental design for a helmet, as shown and described. 